Glass-grinding table.



E. BAGNALL.

GLASS GRINDNG TABLE.

AYPLICATION FILED AUG.7, 1914.

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E. BAGNALL.

GLASS GRINDING TABLE.

WPLIGATION FILED AUG.?,1914

l l, l 2l ,45% Patent@ Dec. 15, 1914:.

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iliillliiirlr Sitka i S ATEN seien EDWARD BAGNALL, OF PITTSBURGH,PENNSYLVANIA, ASSIGNOR TO ZOFFER PLATE GLASS MANUFACTURING CGMPANY, OFPITTSBURGH, PENNSYLVANIA, A. COR- PORATION OF WEST VIRGINIA.

GLASS-GRINDING TABLE.

Specification of Letters Patent.

Patented Dec. 15, 1914.

Be it known that l, lewaia) BaoNALL, a citizen o'l' the United States.residing at Pittsburgh. in the county of Allegheny and State olPennsylvanii, have iniented certain new and useful linproi'muents in(Erlass- Grinding Tables, of which the following is a specification. f

My invention relates to iuiproveinents' in apparatus for grinding,smoothing and polishing plate glass, and it has tor its object toprovide effective and economical means for cusliionincr and holding theglass plates upon 'the upper portion olf the rotating),` table, inconnection with. the oper-ations peilbi'iiied by the usual superimposedrunners.

In carrying out my invention the rotatable supporting table is providedwith means for exhausting the air trom its interior, and a plurality ofnumerous supporting resilient cups, the central portions of which are incommunication with such vacuum cavity, adapted to support the plate orplates and hold them by suction, or exterior air pressure, the cupsbeing so constructed as to utiliz/.e automatically closing check valvedevices .tor preventingr ingress of air through the exposed cups.

Preferred constructions ot' the invention are shown in the accompanyingdrawings, in which- Figurelis a. plan View of the apparatus, showing'certain of the exposedcups provided withinelosinp` valve devices.l'-`i,q.2is a ver tical sectional view tln'fough the table, showing theglass supliorted upon sonne ot the cups bet'ore air exhaustion iseffected. Fig. 3 is a sectional detail view oi a portion ot' the table,showing the plate resting on the cups bei? "e the air is exhausted, oneol the cups being exposed. Fig. ft is a sectional detail view, showingthe action olE the glass on the cups when the :.ir is exhausted. Fig. 5is a view similar to Fig. 3, but showing the table provided withsupplementalsupporting abutments. Fixer. (i is a broken plan View,showin;` the said construction.

The rotatable ldass supporting table A is preferably made ot an upperwall 2 and a lower wall $5 providing an interior air cavity 4. rThetable made in a plurality of Sections and divided at the line 5,' thesecA tions constitutingr units ol the complete table, connected asshown, and providing for continuous circulation ot the air throughoutits entire interior, by means of the ccntral, connnon rotatable airconduit or hollow spindle 6. Said spindle may be connectedwith theinterior of the table in any suitable manner, operating as a hollow'Inast which may act as the main steinof the table,

and which may be provided with anA actuating drum or pulley 7. Such drumis rigidly incorporated with the table or its central mast in anysuitable manner, as shown, resting upon roller or ball bearings S, beingdriven by a pulley or cable engaging the peripheral groove 9, as will bereadily understood.

10 represents an air exhausting device of any suitable constructionhaving an operating steam pipe connection 11, an exhaust teri'ninal 12,and a suction conduit 13. Said conduit makes a tclescoping engagementwith the lower end of the rotatable mast 6, as indicated at 14, beingprovided with suitable packingr or other customary or necessaryattachments or parts, whereby con munieation may be established with theinterior cavity -'lot the table at all times.

The upper wall 2 of the table, or of the several connected unitscomprising' it, is provided with a numerous series of attaching bushings15 tapped into the shell 2 and having;r a central opening, preferablytapered, into which is inserted the hollow nipple 1G o'l. the resilientcup 17. preferably oi rubber, is so constructed as to bear upwardlyunderl'ieath the underside of the plate a, as shown in Figs. 2 and 3.and,

to be compressed by the weight of the plate and the exterior atmosphericpressure when Said cup, which is the air is exhausted from the interioroi" the table and through the hollow nipples 1G, as in Fig. 4.

Tn utilizing' the invention, the plates c, which are usuallyrmtane'ular, leave uncovered certain oi' the cups which are thus notutilized. llor the purpose oi closing' them against atmosphericcircuhation, each is provided with a check valve ih. which may Il@ inthe torni ot' a rubber or other ball. and which will tightly seat in theupper portion ot the nipple at the ba c ol' the cup. ell'ecing thedesired closure, For such purpose, and to insure seating ol' the valveIH below the plane ol' the under side oll the glass. when depressed byair pressure, the valves are 'compress-rd, as indicated in Fig. 4,thereby bringilng all ol the several plates down to a common level, andwliereby the grinding, smoothing a'nd polishing operations of therunners may be readily aeeoniplished.

It' itlis desired to space the cups apart, or in any ease, to provideintervening supports` Jfor the glass plate, supporting abutnients of anysuitable kind may be extended upwardly from the main surface et thetable to receive `the glasf in its lo\\ered position, and assist in thesipporting af'iionV of the cups. Such abutmen may be of any suitableconstruetion, as shown in Figs. 5 and G, wherein transverse intersectingribs 20 extend upwardly from the upper vfall 2 of the table and betweenadjacent cups, throughout the area of the table. These may be of anysuitable construction or arrangement, and Will also assist inmaintaining a uniform level of the glass.

The advantages of the invention Will be readily understood andappreciated by all those familiar with this class ol. apparatus. Itobviates the necessity of the usual cen'ienting or other laborious andexpensive methods in vogue for holding the glass plates to the table,admitting' ot their easy and quick removal or reversal upon admissionoi. air to the interior. blut-.h admission may be effected by anysuitable valve mechanism or by operation oi the pump member l0.

The number ot' the cups, their arrangement, shape or other features ordetails of construction may be variously changed or modified by theskilled mechanic, but all such are to be considered as Within the 'scopey of the following claims.

`What I claim is:

1. A rotatable glass grinding table having a hollow interior, means forexhausting the air therefrom, and a plurality of individual suction cupsof resilient material located onn up-per supporting wall, thecombinationwith said wall efr; plurality of individuallyfinserted suction oups eaehhaving an air eXn haust opening therethrough and provided with aremovable cheek valve device, substantially as 'set forth.

4. In afrotatable glass supporting table oit the class described havingan interior vacuum cavity and an upper supporting Wall provided withupwardly projecting supporting abutments; the combination With saidupper wall of a'series of colnpressible resilient suetion eupslecatedbetween said abutments, having air circulation openings therei through,andmdapled to be depressed to the Jupper level of said abutmentssubstantially as set fortln! l'n testimony whereof I hereunto aiiix mysignature in the presence of two Witnesses.

EDNARD BGNALL.

AlVitne-sses:

C. M. CLARKE, Fnnnli STAUn.

